M3 Noise from rear

[MFun]

Hi guys, New here and wanted to say 'Hi' to everybody. I have a couple of questions which I hope you guys can help answer. When I perform an acute turn on my M3, I hear a grinding sound from somewhere at the back of the car. This hapens intermittently esp if I am turning on a metal grate. Can this be the M diff working? Also has anybody changed the oil in the SMG transmission? How often should this be done? What about the power steering oil?Thanks in advance k:

 

[The Necessary]

A clunking sound?

That's the diff.

Nope, never changed the power steering or SMG oil.

 

[adliz]

welkam mfun..

had the same symtom.. i changed the diff oil.. problem solved..

someone told me we shud change the gearbox oil every 25k-30k km.. i dun think u can change the oil inside the smg hydro unit..

 

[kl_mafia]

i dont own an M3, but i think it is due to air bubble trapped in the differential oil. like adliz mentioned, u need to change it

 

[The Necessary]

Huh? Air bubbles?!

Dude, LSDs make clunking noises when manouvering in tight spots at low speed because they're trying to do what they're designed to do.

 

[tony5050]

guys,

i got my SMG oil changed before but it has not solve the clunking sound which should be from the rear diff..so i think rear diff oil change is the solution..my 2 cents though :lol:

 

[bmwsideways]

Does M Series LSD have noise as a Japs LSD?

 

[The Necessary]

I think all LSDs make "noise" during low speed tight manouvering. At least that's been my experience with the 2 vehicles I've had that came equipped with.

It's a sign that it works.

Or you could try jacking both rear wheels up and trying to spin one independently of the other. There should be initial freeplay followed by resistance.

 

[viewfinder]

I don't own a M3 but I have a 4x4 that has LSD. And yes, it makes that noise turning corners when rear wheels are engaged (switch from 2 wheel to 4 wheel). It does not matter whether it's new/old axle oil or with/without LSD oil. Like The Necc said, it's doing what it's designed for...